Confirmed: Cosmic neutrinos exist!

Scientists at the IceCube Neutrino Observatory in Antarctic have verified the existence of the tiny energetic particles known as cosmic neutrinos, which are believed to be produced by some of the most violent phenomena in the universe, including supernovae and black holes.

According to Gizmodo, Live Science and NBC News, researchers at an observatory located deep beneath the ice near the South Pole have spotted the ephemeral, nearly massless particles coming from the Milky Way and from locations beyond our galaxy. Researchers also shed new light on the origins of cosmic rays.

In a new study published Thursday in the journal Physical Review Letters, the IceCube Neutrino Observatory scientists reported that they found 21 high-energy muons in two years worth of data collected by thousands of sub-surface optical sensors. These particles are created when neutrinos collide with another object, providing evidence showing cosmic neutrinos can traverse space.

Next step is to confirm the neutrinos’ origins

IceCube project scientists previously found neutrinos from outside our galaxy two years ago, but in order to confirm the detection they had to make sure that the neutrinos were not originating from the sun or another source in the Milky Way. They did so by searching for neutrinos that had similar energies and were coming from multiple directions at the same speed.

This indicated that the neutrinos were independent of the Earth’s rotation and orbit around the sun, something that is only possible if their source was from outside the galaxy. They also had to filter out muons created when cosmic rays crashed into the planet’s atmosphere, which they did by pointing the observatory through the Earth towards the sky in the Northern Hemisphere.

Of the 35,000 neutrinos recorded between May 2010 and May 2012, less than two dozen of them had high enough energy levels to suggest that they came from cosmic sources, claims LiveScience. The next step is to determine exactly where these muons are coming from, Gizmodo added.

Furthermore, the authors found that the characteristics of the muon neutrinos are not a good fit with several existing models used to explain their origins. While this topic is not discussed at length in their study, they said that the data appears to show that they do not come from gamma-ray bursts or active galactic nuclei, though more research is needed to know for sure.


Image credit: Ice Cube Collaboration